The pJTI™ R4 CMV-TO MCS pA vector is designed for the expression of your gene of interest under the control of the tet-inducible CMV promoter after restriction enzyme cloning and retargeting into the genomic R4 site of a Jump-In™ parental cell line. This vector can be used for inducible or constitutive expression of your gene of interest, depending on which Jump-In™ parental cell line you use. When this vector is retargeted into a Jump-In™ T-REx™ parental cell line, gene expression is controlled by the tet-operon and can be induced by adding doxycycline to the growth media. When used with a Jump-In™ parental cell line such as the Jump-In™ GripTite™ HEK293 cell line, constitutive expression is achieved after retargeting. The R4 sites in the Jump-In™ parental cell lines result in a high retargeting efficiency, requiring less effort and less time than traditional cell engineering methods. Retargeting of Jump-In™ parental cell lines results in creation of an isogenic pool that is sufficient for cell-based experiments without the need for clonal selection. Alternatively, the high retargeting efficiency allows for easy selection of a positive stable clone for expressing your gene of interest.